Organic peroxides, their preparation, and their applications

ABSTRACT

Tetraperoxides of the formula   where X is a bivalent radical such as alkylene; R1 is hydrogen or an organic radical; R2 is alkylene alkoxy carbonyl; and R3 is an organic radical. Method of preparing tetraperoxides by addition reaction between a bis-hydroperoxide and a carbonyl compound to form a dihydroxy diperoxide, followed by condensation of the dihydroxy diperoxide with a tertiary monohydroxide. The tetraperoxides are useful for vulcanizing saturated elastomers, crosslinking plastomers, and initiating radical polymerization.

United States Patent Sacrini et al.

[ Dec. 23, 1975 ORGANIC PEROXIDES, THEIR PREPARATION, AND THEIR APPLICATIONS [75] Inventors: Egeo Sacrini; Claudio Cavallotti,

both of Milan, Italy [73] Assignee: The B. F. Goodrich Company,

Akron, Ohio [22] Filed: June 27, 1973 [21] Appl. No.: 373,934

Related US. Application Data [62] Division of Ser. No. 62,128, Aug. 7, 1970, Pat. No.

[52] US. Cl 260/610 R [51] Int. Cl? C07C 179/00 [58] Field of Search 260/610 R, 474 R, 610 A,

[56] References Cited UNITED STATES PATENTS 3,296,184 l/l967 Portolani et al. 260/610 R 3,775,465 11/1973 Sacrini et al. 260/610 B Primary ExaminerJames 0. Thomas, Jr. Assistant Examiner-W. B. Lone Attorney, Agent, or Firm-Hubbell, Cohen, & Stiefel [57] ABSTRACT Tetraperoxides of the formula dihydroxy diperoxide, followed by condensation of the dihydroxy diperoxide with a tertiary monohydroxide. The tetraperoxides are useful for vulcanizing saturated elastomers, crosslinking plastomers, and initiating radical polymerization.

5 Claims, N0 Drawings ORGANIC PEROXIDES, TI-IEIR PREPARATION,

AND THEIR APPLICATIONS This is a division of-application Ser. No. 62,128, filed Aug. 7, 1970, now U.S. Pat. No. 3,775,465.

BACKGROUNDQF THE INVENTION 1. Field of the Invention The present invention relates to a new series of organic peroxides. More particularly, it relates to a process for the preparation of peroxides having four peroxidic functions, to novel peroxides having four peroxidic functions, and to the use of such peroxides as radical polymerization initiators, vulcanizing agents for elastomers, crosslinking agents for plastomers, and as organic reactants. 5

2. Description of the Prior Art It is well known that organic compounds of a peroxidic nature are important as generators of free radicals and consequently as initiators of free radical polymerizations, as crosslinking agents for plastomers and as vulcanizing agents for elastomers.

THE INVENTION The present invention provides a particular type of new organic peroxides having good stability and low volatility at temperatures higher than room temperature, such peroxides being particularly suitable both as vulcanizers for elastomers and as crosslinking agents for plastomers.

The present invention provides a new series of organic peroxides characterized by the presence of four peroxidic groups, these peroxides being defined by the general formula:

wherein: I

each of R, may be hydrogen, alkyl, haloalkyl, cycloalkyl, halocycloalkyl, alkylcycloalkyl, said groups having l-l5 C, aryl, haloaryl, alkaryl, said groups having 6-15 C, oxyalkyl, 'oxyalkylaryl, or oxycycloalkyl, said groups having l-l5 C;

each of R may be'alkylene alkoxy carbonyl wherein alkylene'group has 1-4 C and alkoxy group has 1 to 4 C such as methylene ethoxy carbonyl,

. 2 arylene, or halo arylene, said groups having 6-18 C. Examples of compounds within the above cited general formula include:

1 a-a' 2-tert.-butyl peroxy-( 3-ethoxycarbonyl -isopropylidene-Z peroxy] 1,3 diisopropylbenzene,

2) a-a[2-tert.buty1 peroxy-(3-ethoxycarbonyl)-isopropylidene-2 peroxy] 1,4 diisopropylbenzene,

3) a-a'[2-cumyl peroxy-(3-ethoxycarbonyl)-isopropylidene-2 peroxy]1,3 diisopropylbenzene,

4) 01-01 [2-cumyl peroxy-( 3-ethoxycarbonyl )-isopropylidene-2 peroxy] 1,4 diisopropylbenzene.

The peroxides of this invention show the unusual properties of being endowed with a good stability and a low volatility at temperatures higher than room temperature. These properties permit the compounds to be readily incorporated both into the plastomers as crosslinking agents, and into elastomers as vulcanizing agents, without giving rise to troublesome secondary phenomena.

This invention provides, moreover, a process for the preparation of the foregoing peroxides, as ,well as of other known tetraperoxides, e.g.,. those disclosed in US. Pat. No. 3,489,730 at column 1, lines 41-59, the contents of which are incorporated herein by reference, through two successive steps. In the first step there occurs an addition reaction between a bishydroperoxide and a carbonyl compound, with the formation of a diperoxide having a double hydroxy function. In the second step there occurs a condensation reaction between the previously obtained diperoxide and a mono-hydroxide of the tertiary type.

According to a preferred embodiment, the desired tetraperoxides are prepared in the presence of a suitable solvent by reacting in the first step (1) an organic carbonyl compound of. the formula: R,CO-R wherein each of R 'and R may be hydrogen, alkyl, haloalkyl, cycloalkyl, halocycloalkyl, alkylcycloalkyl, said groups having 1-15 C, aryl radicals, haloaryl, alkaryl, said groups having 6-15 C, oxyalkyl-, oxyalkylaryL. oxycycloalkyl, said groups having l-l5 C; R may also be an alkylene alkoxy carbonyl wherein alkylene has 1 to 4 C and alcoxy has 1 to 4 C; or R, and R together with the central carbon atom form a cycloaliphatic ring, having 4-16 C, which ring may be alkyl-, halogenor hydroxysubstituted, having l-8 C, with (2) a bis-hydroperoxide of the formula: HOOX-OOH, in which X has the previously defined meaning, the reaction being carried out in the presence of a suitable dehydrating agent and an acid catalyst, at a temperature of from about -30 to +C, preferably from about 1 0C to +50C-. A

The compound thus obtained is a diperoxide of the formula:

' Rl R, HO-(T-OO-X-OO-JL-OH I wherein. t R and R and X have the previously defined meanings.

Examples of compounds embraced by the above formula include:

a) a-a(2-hydr0xy-isopropylidene-2-peroxy) 1,3 diisopropylbenzene;

b) a-a'(2-hydroxyisopropylidene-2-peroxy) 1.4 diisopropylbenzene:

c) a-a'(2-hydroxy-2-phenylethyl-Z-idene-peroxy) 1,3

diisopropylbenzene;

d) a-a[2-hydroxy-( 3-ethoxycarbonyl)-isopropylidene- 2-peroxy] 1,3 diisopropylbenzene;

e) a-a'[2-hydroxy-(3-ethoxycarbonyl)-isopropylidene- 2-peroxy] 1,4 diisopropylbenzene:

a-a'( l -hydroxy-cyclopentylidenel -peroxy) diisopropylbenzene;

a-a( l-hydroxy-cyclopentylidenel -peroxy) diisopropylbenzene;

h) a-a( l-hydroxy-cyclohexylidene-l-peroxy) diisopropylbenzene;

i) a-a( l-hydroxy-cyclohexylidene-l-peroxy) 1,4 diisopropylbenzene;

j) a-a (l-hydroxy-4-tert.-butyl-cyclohexylidene- 1 peroxy) 1,3 diisopropylbenzene;

k) a-a' (l-hydroxy-4-tert.-butyl-cyclohexylidene-lperoxy) 1,4 diisopropylbenzene;

1) 04-01 (l-hydroxy-cyclododecylidene-l-peroxy) 1,3

diisopropylbenzene;

m) a-a' (l-hydroxy-cyclododecylidene-l-peroxy) 1.,4

diisopropylbenzene;

n) a-a' (2-hydroxy-n-butyliden-Z-peroxy) 1,3 diisopropylbenzene;

) 01-11 (4-hydroxy-2,6,8 trimethyl nonylidene-4- peroxy) 1,3 diisopropylbenzene;

p) a'a' [2-hydroxy-(3 phenyl)-propylidene-2-peroxy] 1,3 diisopropylbenzene.

The peroxides defined by the foregoing formula are new compounds, and are useful as initiators of radical polymerizations.

The diperoxides obtained as described above are then reacted in the second step of the process, with mono-hydroperoxides in the presence of suitable dehydrating agents and catalysts of an acid nature at a temperature between about -30 and +80C, preferably between about -l0 and +50C. I

Examples of bis-hydroperoxides which are suitable for use in the first step of the process include: diisopropylbenzene-l,3-dihydroperoxide; diisopropylbenzenel,4-dihydroperoxide; 2,5-dimethyl-2,S-dihydroperoxyhexane; 2,5-dimethyl-2,S-dihydroperoxide-hexane-3; 2,5-dimethyl-2,5-dihydroperoxy-hexyne-3; etc.

Examples of carbonyl compounds suitable for use in the first step of the process include: aliphatic ketones such as methyl ethyl ketone, acetone; substituted aliphatic ketones such as ethyl-acetacetate; cyclo-ketones such as cyclopentanone, cyclohexanone and cyclododecanone; cyclo-alkyl-ketones such as 4-terbutyl cyclohexanone; alkylarylaldehydes such as cinnamaldehyde; alkylheterocyclic aldehydes such as furyl acrylic aldehyde.

The mono-hydroperoxides which may be used in the second step of the process are of the type: R OOH wherein R has the above defined meaning, preferably wherein a tertiary carbon atom is bound to the hydroperoxide group. Examples of such mono-hydroperoxides include: tert.-butyl hydroperoxide and substituted tert.-butyl hydroperoxides, cumyl hydroperoxide and substituted cumyl hydroperoxides, methyl-cyclohexyl hydroperoxide, 2-methyl-2 hydroperoxide-butyn-3, menthane hydroperoxide, etc.

Solvents suitable for use in this invention include linear aliphatic hydrocarbons having 6-lO C; linear aliphatic halogenated hydrocarbons having 1 or 2 C and 1 to 4 Cl; cycloalipha tichydrocarbons having 6-10 C; aromatic hydrocarbons having 6-9 C, which may be halogenated with l or 2 Cl; ethers for instance, ethyl ether. 1

The molar ratio between the bis-hydroperoxide and the carbonyl compound used in the addition reaction should be between 1:1.2 and 1:10, and preferably between 1:l.5 and 1:5. Catalysts of an acid nature may be of the HCl, H 80, and HClO type. I

For the second step of the process, wherein a condensation reaction takes place, the molar ratio of diperoxide having a double hydroxy function to monohydroperoxide should be between 1:2 and 1:10, and preferably between 1:3 and 1:5.

As previously noted, the overall process of this invention can be employed to prepare a wide variety of tetraperoxides, many of which are known, many of which are new. Examples of tetraperoxides which can be made by the process of this invention include the following:

l) a-a' (2-cumyl peroxydsopropylidene-2-peroxy) 1,3

' diisopropylbenzene;

2) 01-11 (2-cumyl peroxy-isopropylidene-Z-peroxy) 1,4

diisopropylbenzene;

3) 01-01 (2-tert.-butyl-peroxy-2-phenyl ethyl-2-idene-2- peroxy) 1,3 diisopropylbenzene;

4) 01-01 (2-tert.-butyl-peroxy-2-phenyl ethyl-2-idene-2- peroxy) 1,4 diisopropylbenzene;

5) 01-04 (2-cumyl peroxy2-.phenyl ethyl-2-idene-2- peroxy) 1,3 diisopropylbenzene;

6) a-a (2-cumyl peroxy-2-phenyl ethyl-2-idene-2- peroxy) 1,4 diisopropylbenzene;

7) 11-04 [2-tert.-butyl peroxy-(3-ethoxycarbonyl) isopropylidene-Z-peroxy] 1,3 diisopropylbenzene;

8) a-a' [2-tert.butyl peroxy-(3-ethoxycarbonyl) isopropylidene-Z-peroxy] 1,4 diisopropylbenzene;

9) 01-11 [2-cumyl peroxy-(3-ethoxycarbonyl)-isopropylidene-Z-peroxy] 1,3 diisopropylbenzene;

l0) a-a' [Z-cumyl peroxy(3-ethoxycarbonyl)-isopropylidene-Z-peroxy] 1,4 diisopropylbenzene;

11) 01-01 (l-tert.-butyl peroxy-cyclopentylidene-lperoxy) 1,3 diisopropylbenzene;

12) 01-11 (1-tert.-butyl peroxy-cyclopentylidene-lperoxy) 1,4 diisopropylbenzene;

13) 01-01 (l-cumyl peroxy-cyclopentylidene-l-peroxy) 1,3 diisopropylbenzene;

14) 11-01 (l-cumyl peroxy-cyclopentylidene-l-peroxy) 1,4 diisopropylbenzene;

15) 01-01 (l-tert.-butyl peroxy-cyclohexylidene-lperoxy) 1,3 diisopropylbenzene;

l6) a-oz' (l-tert.-butyl peroxy-cyclohexylidene-lperoxy) 1,4 diisopropylbenzene;

17) a-a' (l-cumyl peroxy-cyclohexylidene-l-peroxy) 1,3 diisopropylbenzene;

18) 11-01 (l-cumyl peroxy-cyclohexlidene-l-peroxy) 1,4 diisopropylbenzene;

l9) a-a' l-tert.-butyl peroxy-4 tert.-butyl-cyclohexylidene-l-peroxy) 1,3 diisopropylbenzene;

20) a-a' (l-tert.-butyl peroxy-4 tert.-butyl-cyclohexylidene-l-peroxy) 1,4 diisopropylbenzene;

21) 01-01 .(l-tert.-butyl peroxy-cyclododecylidene-lperoxy) 1,3 diisopropylbenzene;

22) a-a' (l-tert.-butyl peroxy-cyclododecylidene-lperoxy) 1,4 diisopropylbenzene;

23) a-ct (2-tert.-butyl perxy-n-butylidene-Z-peroxy) 1,3 diisopropylbenzene;

24) a-a (4-tert.-butyl peroxy-2,6,8,.trimethyl nonylidene-4-peroxy) 1,3 diisopropylbenzene;

25) a-a [2-tert.-butyl peroxy-( 3 phenyl) propylidene- 2-peroxy] 1,3 diisopropylbenzene;

26) 11-01 [l-cumyl-peroxy-(4-tert.-butyl) cyclohexylidene-l-peroxy] 1.3 diisopropylbenzene.

Both the hydroxyl diperoxides and the tetraperoxides obtained according to this invention are soluble in aliphatic and aromatic hydrocarbons, chlorinated ali-, phatic and aromatic solvents, aliphatic alcohols, and aliphatic esters.

According to another and particularly interesting aspect of this invention, it has been found that the peroxides of this invention act as excellent vulcanizing agents for saturated elastomers, crosslinking agents for plastomers, and as initiators for radical polymerizations.

vulcanization of the ethylene-propylene copolymer is carried out at a temperature comprised between about 140 and 190C, preferably between about 150 and 180C, for periods of from about 5 to 200 minutes, preferably between about 5 and minutes.

The concentration by weight of the peroxide should be between about 0.5 and 10 percent, preferably between about 2 and 5 percent, based on the elastomer.

A particularly suitable vulcanization recipe is the following:

ethylene/propylene copolymer 100 parts carbon black 80 parts 7.nO l 10 parts sulfur 0.15 05 parts peroxide 0.005 0.02 parts The use of the peroxides of the invention as crosslinking agents for plastomers finds specific application for polyolefins, particularly polyethylene, inasmuch as its mechanical resistance at high temperatures is improved, its brittleness at low temperatures is decreased, and its solubility in aliphatic hydrocarbons, aromatic hydrocarbons, and chlorinated hydrocarbons is decreased. Moreover, the resistance of the polymer to light, to weather and to aging is improved.

The crosslinking is carried out at a temperature comprised between about 100 and 200C, preferably between about l45 and 165C, at a pressure between about 50-200 kg/cm for a period of time of from about 5 to 60 minutes, preferably from about 10 to 30 minutes.

The concentration by weight of the peroxide is between about 0.5 and 10 percent, preferably between about 2 and 5 percent, based on the plastomer.

The most significant advantages offered by the use of the peroxides according to this invention in the vulcanization of saturated elastomers and in the crosslinking of plastomers, are:

l. The capability of obtaining virtually odorless canized and crosslinked products;

2. Absence of blooming phenomenai 3. Short vulcanization times and low vulcanization temperatures;

4. lmproved effectiveness remains unchanged even in the presence of conventional additives such as filters, reinforcing agents, additives, co-agents, plasticizers, pigments and anti-oxidants.

vul-

The following examples further illustrate the invention. All parts are by weight unless otherwise stated.

EXAMPLE 1 200 cc of ethyl ether, 60.6 g of 1.3-diisopropylbenzene-bis-hydroperoxide-sodium salt at 67%, 51 g of cyclopentanone at 99% and 20 g of ground anhydrous calcium chloride, were introduced into a flask provided with a stirrer.

This mixture was cooled down to from *15 l0C and over a 20 minute period there were slowly introduced 60 g of HCl at 36 percent. The mixture was then stirred for 1 hour at -5C. The ether solution was then washed with water and treated with anhydrous sodium sulfate.

The 04-01( l-hydroxy-cyclo pentylidene-l-peroxy) 1,3 diisopropylbenzene thus obtained (53 g determined analytically) showed the following characteristics:

lodometric titre 987! Hall life 30 minutes at 98C Decomposition temperature 45C C "/1: found 66.40 (calculated 66.98)

H 71: found 8.2 (calculated 8.69)

ln a 10% toluene solution after hrs. at 40C no degradation occurred.

EXAMPLE 2 53 g of a-a( 1-hydroxy-cyclopentylidene-l-peroxy)1,3 diisopropylbenzene obtained according to Example 1 and dissolved in 200 cc of ethyl ether, 44 g of tert. butyl hydroperoxide at 80%, and 40 g of ground anhydrous calcium chloride, were introduced into a flask provided with a stirrer.

The ether solution was then cooled down to 10C and over a 5 minute period there were introduced 20 g of hydrochloric acid at 36 percent. The temperature was permitted to rise to 0C and the solution was stirred for 1 hour at 0C.

The ether phase was then washed, first with water, then with NaOH at 5 percent, and then again with water. The solvent was then-removed under vacuum at 30C, thereby obtaining 69 g of product, namely, aa'( l-tert.-butyl peroxy-cyclopentylidenel peroxy) 1,3 diisopropylbenzene.

The product thus obtained showed the following characteristics: 1

d 0.945 n,,-'"' 1.447 lodomctric titre: 99% Decomposition temperature: 1 14C Half life at 123C: 30 minutes /1: found 66.5 (calculated 66.88) H'/(: found 94 (calculated 9.36)

EXAMPLE 3 300 cc of ethyl ether, 41.8 g of 1,4-diisopropylbenzene bis-hydroperoxide at 97.3 percent, 37.8 g of 4- tert-butyl-cyclohexanone at 98 percent, and 18 g of ground anhydrous calcium chloride were introduced into a flask provided with a stirrer.

The mixture was then cooled down to 0C and over a 5 minute period there were introduced 24 g of HO at 36 percent. The temperature was maintained at 0C and the mixture was kept under stirring for 1 hour.

30 minutes lodometric titre Decomposition temperature Half-life at l 12C C 76: found 70.4 (calculated 71.87) H "/1: found 10.] (calculated 10.18)

EXAMPLE 4 150 g of ether solution containing 66 g of a-a'( 1- hydroxy-4-tert. butyl-cyclohexylidenel peroxy) l ,4- diisopropylbenzene obtained according to Example 3, 44g of tert. butyl hydroperoxide at 80 percent, and 42 g of ground anhydrous calcium chloride were introduced into a flask provided with a stirrer.

The solution was then cooled down to 5C and over a 5 minute period there were introduced 30 g of HCl at 36 percent. Care being taken not to exceed C, the solution was then left under stirring at this temperature for 1 hour. The ether phase was washed with water, then with NaOH at and then again with water.

The solvent was subsequently removed under vacuum at C, thereby obtaining a residue (76 g) identified as a-a( ltert.butyl-peroxy-4-tert.-butylcyclohexylidene- 1 peroxy) 1,4 diisopropylbenzene and having the following characteristics:

30 minutes EXAMPLE 5 200 cc of benzene, 81 g of 1,3-diisopropylbenzenebis-hydroperoxide-sodium salt at 67 percent, 33.5 g of cyclohexanone at 99 percent, and 25 g of ground anhydrous calcium chloride were introduced into a flask provided with a stirrer.

The mixture was then cooled down to 10C and over a period of 30 minutes there were slowly introduced 80 g of HCl at 36 percent. The mixture was then left under stirring for 1 hour at 5C.

The benzene solution was then washed with water and thereafter was dehydrated with anhydrous sodium sulfate.

The a-a( l-hydroxy-cyclohexylidene-l-peroxy)1,3- diisopropylbenzene thus obtained (71 g determined analytically) was maintained in solution. This product showed the following characteristics:

9871 55C 30 minutes EXAMPLE 6 Into a flask fitted with a stirrer were introduced 71 g of a-a( 1hydroxy-cyclohexylidene-l-peroxy)1,3- diisopropylbenzene dissolved in 200 cc of benzene (obtained according to Example 5), 58 g of tert.-butyl hydroperoxide at percent, and 45 g of ground anhydrous calcium chloride.

The benzene solution was cooled down to 10C and over a 5 minute period there were introduced 27 g of hydrochloricacid at 36 percent. The solution was then left under stirring for 1 hour at -5/0C. The organic phase was then washed, first with water, then with NaOH at 5 percent, and then again with water.

The benzene solution was then filtered on a layer of anhydrous sodium sulphate and celite and the solvent was removed under vacuum at 30C.

Thereby was obtained 91 g of a product identified as a-a( ltert.butyl-peroxy-cyclohexylidenel peroxy) 1,3-diisopropylbenzene. The product showed the following characteristics:

lodometric titre: 98.5% Decomposition temperature: 1 13C Half-life at C 31 minutes C 7:: found 67.5 (calculated 67.81) H "/0: found 9.6 (calculated 9.6)

EXAMPLE 7 Into a flask provided with a stirrer were introduced 200 cc of benzene, 50 g of l,3diisopropylbenzene-bishydroperoxide (sodium salt) at 60 percent, 15.8 g of methylethylketone, and 30 g of ground anhydrous calcium chloride. The mixture was cooled down to 5 to 0C and over a 30 minute period there were then slowly introduced 49 g of HCl at 36 percent. The mixture was then stirred for 1 hour at 0C. The benzene solution was washed with water and then dehydrated with anhydrous sodium sulfate.

The a-a'( 2-hydroxy-n-butyliden-2 peroxy) 1 ,3-diisopropylbenzene thus obtained (37 g determined analytically) showed the following characteristics:

lodometric titre: 97% Decomposition temperature: 50C Half-life at 122C 30 minutes C /r-: found 65.3 (calculated 64.84) H 71': found 9.1 (calculated 9.25)

EXAMPLE 8 Into a flask provided with a stirrer were introduced 37 g of a-a(2-hydroxy-n-butyliden-2peroxy)1,3- diisopropylbenzene (obtained according to Example 7), dissolved in 200 cc of benzene, 40 g of tert.-butyl hydroperoxide at 75 percent, and 40 g of ground calcium chloride. The benzene solution was then cooled down to 5C and over a 10 minute period there were introduced 30 g of hydrochloric acid at 36 percent. The temperature was allowed to rise to +5C and the solu tion was stirred for 1 hour at this temperature. The benzene phase was then washed with water, then with NaOH at 5 percent, and again with water.

The solvent was then removed under vacuum at 30C, thereby obtaining 39.5 g of a slightly straw-colored liquid residue identified as a-a( 2 tert.-butylperoxy-n-buty1iden-2 peroxy) 1,3-diisopropylbenzene. This product showed the following characteristics:

lodomctric titre: 94.6% Decomposition Temperature: 105C Half-life at 1 14C 30 minutes:

C It: found 65.8 (calculated 65.34) H 7L: found 9.7 (calculated 9.79)

EXAMPLE 9 Into a flask provided with a stirrer were introduced 100 cc of benzene, 100 g of 1,3-diisopropylbenzenebis-hydroperoxide (sodium salt) at 60%, 81 g of 2,6,8- trimcthyl-4-nonanone and 30 g of ground anhydrous calcium chloride. The mixture was then cooled down to 5C to C, and over a 30 minute period there were introduced 95 g of hydrochloric acid at 36 percent. The temperature rose to +C and the mixture was then left under stirring for 1 hour. The benzene phase was then washed with water and then treated with anhydrous sodium sulfate.

The a-oz'(4hydroxy-2,6,8 trimethyl-nonylidene-4- peroxy) 1,3-diisoprophylbenzene'thus obtained (1 g determined analytically) showed the following characteristics:

C 7:: found 71.7 (calculatcd,72.68) H '4: found 10.9 (calculated 11.18)

EXAMPLE l0 1 15 g of 111-01 (4-hydroxy-2,6,8-trimethyl-nonylidene- 4 peroxy)1,3-diisopropylbenzene (obtained according to Example 9) dissolved in 100 cc of benzene, 79.5 g of text. butyl hydroperoxide at 75 percent, and 40 g of ground anhydrous calcium chloride were introduced into a flask provided with a stirrer.

The solution was then cooled down to -5C and over a 10 minute period there were introduced 40 g of hydrochloric acid at 36 percent. Due to the exotherm, the temperature rose to +5C and the solution was then left under stirring at +5C for 1 hour.

The benzene phase was washed with water, then with NaOH at 5 percent, and again with water. The solvent was then removed under vacuum at C, thereby obtaining a liquid residue of a slight brownish color which was identified as a-oz'(4-tert.-butyl-peroxy-2,6,8- trimethyl-nonylidene-4-peroxy) l ,3-diisopropylbenzene, which product had the following characteristics:

lodomctric titre: 92'71 Decomposition temperature: 109C Half-1ife at 1 16C 30 minutes C found 71.3 (calculated 71.50) H /r: found 11.1 (calculated 11.18)

EXAMPLE 1 1 Into a flask provided with a stirrer there were introduced 300 cc of benzene. 65.4 g of 1,4-diisopropylbenzenebis-hydroperoxide at 95 percent, 50 g of cyclododecanone, and 50 g of ground anhydrous calcium chloride.

mined analytically) showed the following characterisllCSI lodometric titre: 98% Decomposition temperature: 59C Half-lifc at l 14C: 30 minutes C "/1: found 73.3 (calculated 73.17) H "/1: found 10.3 (calculated 10.58)

EXAMPLE 12 Into a flask provided with a stirrer were introduced 80 g of a-a'(1-hydroxy-cyclododecylidene-1 peroxy) 1,4-diisopropylbenzene (obtained according to Example l 1) dissolved in 300 cc of benzene, 66.7 g of ten.- butyl-hydroperoxide at 66.7 percent, and 40 g of ground anhydrous calcium chloride-The benzene solution was then cooled down to 0C and over a 10 minute period there were introduced 5 g of hydrochloric acid at 36%.

The temperature was then allowed to rise to +5C and the solution was then stirred for 1 hour at this temperature (+5C). The benzene phase was then washed with water, with NaOH at 5%, and then again with water.

The solvent was then removed under vacuum at 40C, thereby obtaining 48 g of a yellow liquid residue identified as a-a(1-tert.-butyl-peroxy-cyclododecylidene-l peroxy) 1,4-diisopropylbenzene. The product showed the following characteristics:

30 minutes C '70: found 70.2 (calculated 71.89) H found 10.9 (calculated 10.7)

EXAMPLE 13 Into a flask provided with a stirrer, were introduced 50 cc of benzene, 50 cc of ethyl ether, 60.6 g of 1.3- diisopropyl-benzene-bis-hydroperoxide (sodium salt) at 67 percent, 27.7 g of benzyl-methyl-ketone at 97 percent, and 30 g of ground anhydrous calcium chloride. This mixture was then cooled down to 15C and then were slowly added, over a 30 minute period, 60 g of HCl at 36 percent. Thereafter the mixture was kept under stirring for 1 hour at 5C.

The organic solution thus obtained was then washed with water and then was dehydrated with anhydrous sodium sulfate. The product thus obtained (37 g determined analytically), identified as a-a[2-hydroxy-(3- phenyl) propylidene-2 peroxy] l,3-diisopropylbenlodotnetric titration:

93.5% Decomposition temperature: C Half-life at 104C: 30 minutes C 4: found 71.9); (calculated 72.85) H In: found 7.471 (calculated 7.74)

EXAMPLE 14 Into a flask provided with a stirrer were introduced 37 g of oz-a[2-hydroxy-(3-phenyl)propylidene-2 peroxyl] 1 ,3 diisopropylbenzene (obtained according to Example 13) dissolved in 50 cc of benzene and 50 cc of ether, 45.2 g of tert.butyl hydroperoxide at 80 percent, and 20 g ground anhydrous calcium chloride. This solution was then cooled down to C and in over a minute period there were added 20 g of hydrochloric acid at 36 percent.

The exotherm caused the temperature to rise to +5C and the solution was maintained at this temperature for one hour under stirring. Thereafter the organic phase was washed with water, with NaOH at 5 percent, and again with water until neutrality.

Then the solvent was removed under vacuum at 50C, thereby obtaining a slightly opalescent liquid residue (44 g), identified as a-a[2-tert.-butyl-peroxy- (3-phenyl )propylidene-2 peroxy] 1,3-diisopropylbenzene, having the following characteristics:

lodometric titration: 7571 Decomposition temperature: 132C Ha1flife at 123C: 30 minutes C "/1: found 72.9% (calculated 71.44) H "/1: found 8.571 (calculated 8.52)

EXAMPLE l5 Into a flask provided with a stirrer were introduced 50 cc of benzene, 50 cc of ethyl ether, 21.4 g of 1,3- diisopropylbenzene-bis-hydroperoxide (sodium salt) at 67 percent, 19.3 g of 4tert.-butyl-cyclohexanone, and 10 g of ground anhydrous calcium chloride. This mixture was then cooled down and over a 20 minute period there were introduced dropwise 20 g of HCl at 36 percent. The mixture was then subjected to stirring for 1 hour at 5C.

The organic solution was washed with water and was then dehydrated with anhydrous sodium sulfate. The residue (32 g determined by analysis), identified as a-a[ 1-hydroxy-(4-tert.-butyl)-cyclohexylidenel peroxy]1,3-diisopropylbenzene, was kept in a solution. An analytical isolated sample showed the followiing characteristics:

95% 78C 30 minutes EXAMPLE l6 Into a flask provided with a stirrer were introduced 32 g of a-a[ l-hydroxy-(4-tert.-butyl)cyclohexylidenel peroxy] 1,3-diisopropylbenzene, dissolved in 50 cc of benzene and 50 cc of ether, and g of anhydrous calcium chloride. Over a period of minutes there were then introduced into the mixture, at a temperature of l 5C, 43.9 g of cumene hydroperoxide at 83.4 percent. The solution was cooled down again to 15C, and there were introduced 10 g of HCl at 36 percent over a 10 minute period. The exotherm caused the temperature to rise to --5C and the solution was then left under stirring for one hour at between 5 and 0C.

The organic phase was washed with water, with NaOH at 5%, and then again with water until reaching neutrality. The solvent was then removed under vacuum at 50C, thereby obtaining a slightly oily residue, identified as an a-a'[l cumyl-peroxy-(tert.-butyl)cyclohexylidene-l peroxy]1,3-diisopropylbenzene, and it showed the following characteristics:

lodometric titre: '7: Decomposition temperature: 1 14C Half-life at 125C: 30 minutes C "/1: found 75.171 (calculated 74.4) H "/1: found 85% (calculated 8.52)

EXAMPLE 17 200 cc of n-hexane, 50 g of 1,3-diisopropylbenzenebis-hydroperoxide-sodium salt at 60 percent, 29 g of acetoacetic acid ethyl ester at 99% and 30 g of ground anhydrous calcium chloride were introduced into a flask provided with a stirrer. The mixture was then cooled down to l05C and over a period of 30 minutes there were introduced 45 g of HCl at 36 percent. The mixture was then left under stirring for 1 hour at 5C. The organic phase was then washed with water and thereafter was dehydrated with anhydrous sodium sulfate. The a-a'[2-hydroxy-(3 ethoxy-carb0nyl)-isopropylidene-2 peroxy] 1,3-diisopropylbenzene thus obtained (43 g determined analytically) showed the following characteristics:

lodometric titre Decomposition temperature 47C Half-life at l 18C 30 minutes C "/1; found 60.1 (calculated 59.24) H found 7.65 (calculated 7.87)

EXAMPLE l8 Into a flask fitted with a stirrer were introduced 43 g of a-a '[2-hydroxy-(3 ethoxy-carbon-yl)-isopropylidene-2 peroxy] 1,3-diisopropylbenzene"(obtained according to example 17) dissolved in 200 cc of n-hexane, 40 g of tert.-butyl hydroperoxide at 75 percent and 40 g of ground anhydrous calcium chloride. The solution was cooled down to 10C and over a 10 minute period there were introduced 30 g of HCl at 36 percent. The temperature was allowed to rise to 0C, and the solution was stirred for 1 hour at this temperature. The organic phase was then washed with water, then with NaOH at 5 percent and then again with water. The solvent was removed under vacuum care being taken not to exceed 30C, thereby obtaining 47 g of slightly yellow-coloured viscous residue identified as a 0:[2- tert.-butyl-peroxy(3 ethoxy-carbonyl) isopropylidene- 2 peroxy] 1,3-diisopropylbenzene.

This product showed the following characteristics:

L 0,937 n,,""" 1.489 lodometrie titre 97 7c Decomposition temperature 109C Half-life at 1 18C 30 minutes C A: found 61.4 (calculated 60.93) H found 8.63 (calculated 8.63)

EXAMPLE 19 Into a flask provided with a stirrer were introduced lodomctric titre Decomposition temperature 45C Half-life at l l(' 30 minutes '71: found 58.6 (calculated 59.24) H '71: found 743 (calculated 7.87)

EXAMPLE 20 150 cc of benzene containing 29 g of aa'[2-,hydroxy (3-ethoxycarbonyl) isopropylidene-Z-peroxy l ,4 diisopropylbenzene (obtained according to example 19) and l5 g of anhydrous calcium chloride were introduced into a flask fitted with a stirrer. Over a 20 minute period to l5C there were introduced 43.9 g of tert.- cumyl hydroperoxide at 83.4 percent.

The temperature was maintained to C and over a 10 minute period there were introduced 10 g of HCl at 36 percent. Due to the exotherm the temperature rose to 5C and at this temperature the solution was then left under stirring for 1 hour. The organic phase was then washed with water, then with NaOH at 5 percent and again with water until neutrality.

The solvent was removed under vacuum at 30C thereby obtaining 38 g of a slightly oily; straw-colored residue identified as aa[2-cumyl-peroxy (3-ethoxy carbonyl) isopropylidene-Z peroxy] 1,4 diisopropylbenzene having the following characteristics:

"1F" 1,521 lodometric titre 93 '70 Decomposition temperature I2IC Half-life at l22C 30 minutes C 7!: found (15.3 (calculated 66.82) H "/1: found 7.32 (calculated 7.74)

EXAMPLE 21 Vulcanization Vulcanization tests were carried out on mixes of an ethylene-propylene copolymer having a molar ratio ethylene/propylene /50 and a viscosity Mooney ML l 4) C 35 in Table I there were compared the vulcanization rates determined on the same mixes, containing as peroxides, respectively:

01- oz'( l-tert.-butyl-peroxy-cyclopentylidenel -peroxy) l ,3-diisopropylbenzene; I

aa( l-tert.-butyl-peroxy4-tert.-butyl-cyclohexylidene-l-peroxy) 1,4-diisopropylbenzene;

aa( l-tert.-butyl-peroxy-cyclohexylidene- [-peroxy) 1,3 diisopropylbenzene;

01- a'[2-ter.-butyl peroxy (3-ethoxycarbonyl) isopropylidene-2 peroxy] [,3 diisopropylbenzene;

dicumylperoxide.

The vulcanization rate was determined at 177C on a Monsanto TM-lO rheometer. The mixes used in the test were of the following composition:

ethylenc-propylene copolymer 100 parts carbon black 50 parts ZnO 3 parts sulfur 0.32 parts peroxide 0.0] mol Table 2 reports the physical characteristics of vulcanized products obtained by using as peroxides, respectively:

aa( l-tert.-butyl-peroxy-cyclopentylidenel -per0xy) l ,3-diisopropylbenzene; aa( l-tert.-butyl-peroxy-4-tert.-butyl-cyclohexylidene- 1 -peroxy) l ,4-diisopropylbenzene; 01- oz( l-tert.-butyl-peroxy-cyclohexilidenel -peroxy) l,3-diisopropylbenzene; for vulcanization times comprised between 5 and 60 minutes at C, in comparison with the physical properties of the vulcanized products obtained by using dicumyl peroxide and operating at C for a vulcanization time of 30 minutes (these being the optimal conditions for said peroxide). I

From the results reported in Table 2, it is quite evident that at low-temperatures high vulcanization rates and better physical characteristics of the vulcanized product are obtained with theperoxides of the invention as contrasted to the use of dicumyl peroxide.

TABLE 1 'V ulcanization Rate Vulcanization Peroxide at the RHEOMETER TYPE Parts per I00 g of vulcanization Vulcanization ethylene/propylene temperature time copolymer C minutes g moles l 3 l 3 5,38 0.01 177 5 (CH C00 006 -c0o 00C (CH 1 CH (H 1": E"; (cu i coo oo ioo OO (CN CH I g I! ll 45 TABLE l-continued vulcanization Rate Peroxide vulcanization a! the RHEOMETER TYPE Parts per I g of vulcanization vulcanization ethylene/propylene temperature time copolymer C minutes g moles (CH l COO OOE -OO OOC(CH3) 3 CH3 CH3 ,3 7 [2I'L-bll'y|p.IOlY(3 .lhOXy Gl'bflY|) isopropylidonn-l plroxyJLIi diisopmpylbln zon- Dicumylpcroxidc 2.70 l4 TABLE 2 Physical Characteristics of the Vulcanized Product Peroxide vulcanization Parts per I00 g of Tcmpcrat. Time ethylene/propylene C minute copolymcr moles g CH c 150 5 I 3 I (CH COO OC -CO0 OOC (CH l ),()l 5.38 3 3 l I 3 3 CH CH I! 0 ,"3 ,3 I 5 (cu coo ooc-@coo oocmr l0 3 4 z l 0,0: 6,79 15 3 CH3 n 30 6O CH-C-CH CH -$-CH 3 a 3 3 3 CH 3 CH3 CH I50 5 3 I 3 H) (cu l coo ooc -coo clcu 1 0,01 5,66 l5 s a 3 3 n 30 CH3 CH3 I! Dicumylpcroxidc (),()l 2,70 I 30 Physical properties of the vulcanized product Tensile Elongation Modulus Modulus Modulus l,R.H.D. strength at break 21! I007: at 200% at 300% hardness kg/cm 7c kg/cm kg/cm kg/cm I92 510 23 50 91 65-66 I98 470 25 55 l()8 I87 410 22 54 I04 I98 420 23 6| 1 I9 186 380 25 68 ZOl 350 25 78 68-69 203 340 27 8i 164 202 350 26 75 158 I90 330 28 84 I68 178 340 25 72 I48 I99 490 22 54 I03 460 23 53 NM 203 440 24 56 i '1 l (11-68 202 410 25 63 I26 I88 400 24 57 l23 EXAMPLE 22 On a mix having the following composition:

ethylene/propylene copolymer l parts carbon black 50 [n0 3 sulfur (L32 ma'lZ-lerL-hutyl peroxy (fl-ethoxycarhonyl) isopropylidenel peroxy] L3 diisoprt pylbenzene 00l mol was carried out the vulcanization test at 150C for minutes. The vulcanized product showed the following physical characteristics:

Tensile strength (kg/inn") I85 Elongation at break ('fi 412 Modulus at 2007r (kg/cm) (ml Modulus at 30071 (kg/cm) I08 I.R.H,D. hardness 67-68 EXAMPLE 23 Crosslinking ylidene-l-peroxy) 1,4 diisopropylbenzene, and the known peroxide (dicumylperoxide).

EXAMPLE 24 The determination of the degree of swelling was carried out on the crosslinked product. By degree of swelling is meant the volume of solvent absorbed by unit of volume of crosslinked polyethylene.

The method consists in suspending a small basket or cage containing a crosslinked polyethylene plate of about 0.2 g in a test tube containing 100cc of xylene 0 stabilized with 0.1 g of the phenolic antioxidant 4,4-

thio-bis (3-methyl6tert.-butylphenol). The test is carried out for 21 hours at C. The degree of swelling (S) is determined from the following formula:

wherein:

a weight of the test sample after 21 hours at 80C in xylene, b weight of the test sample before the test, c weight of the test sample after drying at, the end of the test.

density of polyethylene at 80C 107 density of xylene at 80C The obtained results, compared with those in which dicumylperoxide was used, are listed in Table 4.

TABLE 3 Crosslinking of low-density (0.918) polyethylene Physical characteristics. 7

PEROXIDE Moles of Crosslinking Yield Tensile Elongaperoxide Time Temper. point strength tion in l00g minutes C kg/cm kg/cm at break of poly- V 7: ethylene None 20 57,8 73 I50 i: i": lcn l c oi: -lcoo ooclcn i 5 3 so 0,01 20 I45 55 I50 570 f": (m coo 00: Q 00 )3 0,01 20 145 52.7 m 260 CH CH -C| CH CH3 -l; --.cl'| CH CH Dicumylperoxide (ml 20 I45 525) I32 456 TABLE 4 ('rnsslinking of luw-densit) (0.9l X) ptilycthylene Degree of swelling,

PEROXIDF. Mules of Crnsslinking Degree of peroxide swelling in HM) g Time Temper. of polyminutes C ethylene CH CH (CH l coo ooc 0o (cu (H CH 0,0] -0 145 I65 i: a": lcu l coo OOIC FOO OOC(CH a um 20 145 30.2

CH-C-CH (N --CH 3 l 3 3 3 CH3 CH3 Dicumylpemxide ().()l 20 145 1,3

2. A tetraperoxide as claimed in claim 1 which is a.a'-(2-cumyl peroxy-isopropylidene-Z-peroxy) 1,3-

55 diisopropylbenzene,

3. A tetraperoxide as claimed in claim I which is ma (2-cumyl peroxy-is0pr0pylidene-2-peroxy) 1,4 diiso propylbenzene.

4. A tetraperoxide as claimed in claim 1 which is 01-01 0 (2-tert.-butyl peroxy-n-butylidene-2-pe'roxy) 1,3 diisopropylbenzene.

5. A tetraperoxide as claimed in claim I which is a-a (4-tert.-butyl peroxy-2.6.8 trimethyl nonylidene-4- peroxy) 1,3 diisopropylbenzene.

Page I of 3 UNITED STATES PATENT OFFICE CERTIFICATE OF CORRECTION Patent No. 3,928,465 Dated December 23, 1975 Inventor(s) and a It is certified that'error appears in the above-identified patent and that said Letters Patent are hereby corrected as shown below:

Title page, right side, the formula:

n f n R, 00-. oo-x-00--c-R, Should read m-oo-d-oo-x-oo-d-oo-m R R, a I

Column 8, line 18: "Thereby was" should read Thereby were Column 10, line 1: "than" should read then lines 59-60: "oL-oL [2-hydroxy" should read oL-oL' [Z-hydroxy- Column 11, line 23: "1,4988" should read 1.4988

Column 12, line 10: "1,4985" should read 1.4985 line 61: "0,937" should read 0.937 line 62: "1,489" should read 1.489

9 Column 13, line 47: "CZ: found 65,3" should read C7,:

found 65.3 line 48: "11%: found 7,32" should read H7O: found 7.32

' Columns 13-14, column 2 of Table l: G "5,38" should read 5.38

age 2 of 3 UNITED STATES PATENT OFFICE CERTIFICATE OF CORRECTION patent 3,928,465 Dated kDecember 23, 1975 Inventofls) EGEO SACRINI and CLAUDIO CAVALLOTTI It is certified that error appears in the. above-identified patent and that said Letters Patent are hereby corrected as shown below:

Columns 13-14, column 3 of Table 1: "0,01" should read O .01 Column 5 of Table l: "4,5" should read Columns 15-16, column 1 of Table l: "[2-ter.-butylperoxy(3-ethoxycarbonyl) isopropylidene-Z peroxy] 1,3 diisopropylben zone" should read oo-oa' [2-ter.-

butylperoxy(B-ethoxycarbonyl) isopropylidene-Z peroxy] 1,3 diisopropylbenzene Columns 15-16, column 2 of Table l: "5,66 should read 5.66 6,3 6.3

Columns 15-16, column 2 of Table 2: "0,01" should read 0.01 Q

Columns 15-16, column 3 of Table 2: "5,38" should read 5.38

6,79 3 6.79 5, 66 5. 66 2, Column 17, line 26: "0,32" should read 0.32 line 28: "0,01" should read 0.01

Columns 17-18, column 2 of Table 3: "0,01" should read Page 3 of 3 UNITED STATES PATENT OFFICE CERTIFICATE OF CORRECTION Patent; No. 3,928,465 Dated December 23, 1975 I EGEO SACRINI and CLAUDIO CAVALLOTTI It is certified that error appears in the above-identified patent and that said Letters Patent are hereby corrected as shown below:

Columns 17-18, column 5 of Table 3: "57,8" should read 57.8

Columns 19-20, column 2 of Table 4: "0,01" should read Q 0.01

Columns 19-20 column 5 of Table 4: "16,5" should read 16.5

Signed and Sealed this Twenty-eighth Day of September 1976 [SEAL] Arrest.

RUTH C. MASON C. MARSHALL DANN Arresting Officer ('mnmissiunvr of Parents and Tradcmurkx 

1. A TETRAPEROXIDE SELECTED FROM THE GROUP CONSISTING OF
 1. A-A'' (2-CUMYL PEROXY-ISOPROPYLIDENE-2-PEROXY) 1,3 DIISOPROPYLBENZENE;
 2. A-A'' (2-CUMYL PEROXY-ISPROPYLIDENE-2-PEROXY) 1,4 DIISOPROPYLBENZENE;
 2. Alpha - Alpha '' (2-cumyl peroxy-isopropylidene-2-peroxy) 1,4 diisopropylbenzene;
 2. A tetraperoxide as claimed in claim 1 which is Alpha , Alpha ''-(2-cumyl peroxy-isopropylidene-2-peroxy) 1,3-diisopropylbenzene.
 3. Alpha - Alpha '' (2-tert.-butyl peroxy-n-butylidene-2-peroxy) 1,3 diisopropylbenzene;
 3. A tetraperoxide as claimed in claim 1 which is Alpha - Alpha '' (2-cumyl peroxy-isopropylidene-2-peroxy) 1,4 diisopropylbenzene.
 3. A-A'' (2-TERT.-BUTYL PEROXY-N-BUTYLIDENE-2-PEROXY) 1,3 DIISOPROPYLBENZENE;
 4. A-A'' (-TERT.-BUTYL PEROXY-2,6,8 TRIMETHYL NONYLIDENE-4PEROXY) 1,3 DIISOPROPYLBENZENE.
 4. A tetraperoxide as claimed in claim 1 which is Alpha - Alpha '' (2-tert.-butyl peroxy-n-butylidene-2-peroxy) 1,3 diisopropylbenzene.
 4. Alpha - Alpha '' (4-tert.-butyl peroxy-2,6,8 trimethyl nonylidene-4-peroxy) 1,3 diisopropylbenzene.
 5. A tetraperoxide as claimed in claim 1 which is Alpha - Alpha '' (4-tert.-butyl peroxy-2,6,8 trimethyl nonylidene-4-peroxy) 1,3 diisopropylbenzene. 